Microflora, ISVV, 210 chemin de Leysotte, CS 50008-33882 Villenave d'Ornon cedex, France.
Int J Food Microbiol. 2012 Sep 17;159(1):25-9. doi: 10.1016/j.ijfoodmicro.2012.07.024. Epub 2012 Jul 31.
Lactic acid bacteria (LAB) are often exploited to carry out malolactic fermentation in wine. However, a few specific LAB strains and, more precisely, some Pediococcus parvulus strains synthesize a β-glucan, which can be deleterious to wine quality as it confers a ropy texture to the wine that can no longer be commercialized. Although molecular methods exist to detect these unwanted microorganisms, ropy Pediococcus still remain difficult to remove from wine, because of their natural resistance to traditional wine stabilizing treatments. In this work, we show that ropy P. parvulus are resistant to lysozyme. We clearly demonstrate that this resistance may be ascribed to the presence of the β-glucan that forms around the cell a protective barrier against anti-bacteria agents. Moreover, this resistance increases during bacterial growth. We show that using lysozyme with β-glucanase can strongly improve the treatment against ropy strains, in model media as well as red and white wine based media. This work not only brings potential solutions to the wine industry, but also opens interesting perspectives for studying β-glucan producing bacteria which are widespread in the food industry.
乳酸菌（LAB）常用于进行葡萄酒的苹果酸-乳酸发酵。然而，少数特定的 LAB 菌株，更确切地说是一些小葡萄球菌（Pediococcus parvulus）菌株，会合成一种β-葡聚糖，这可能对葡萄酒的质量有害，因为它会使葡萄酒变得粘稠，无法再商业化。尽管存在分子方法来检测这些不需要的微生物，但由于其对传统葡萄酒稳定处理的天然抗性，粘稠的小葡萄球菌仍然难以从葡萄酒中去除。在这项工作中，我们表明粘稠的小葡萄球菌对溶菌酶具有抗性。我们清楚地表明，这种抗性可能归因于β-葡聚糖的存在，它在细胞周围形成了一个保护屏障，防止抗菌剂的侵害。此外，这种抗性在细菌生长过程中会增加。我们表明，在模型介质以及红葡萄酒和白葡萄酒介质中，使用溶菌酶和β-葡聚糖酶可以大大提高对粘稠菌株的处理效果。这项工作不仅为葡萄酒行业带来了潜在的解决方案，也为研究β-葡聚糖产生菌开辟了有趣的前景，这些细菌在食品工业中广泛存在。
